Shimano ST-7S20 cleaning and lubricating because of resinous mechanics

Stap 1 — Orientate shift lever and remove case screw

Loose the socket screw of the clamp with a 5mm hex key.

Stap 2 — Remove Cover

Carefully lift the cover with your fingers.

Stap 3 — Find the error, you want to know

If possible shift carefully threw all seven gears.

Stap 4 — Clean and lubricte the gear

Clean the gear of the shift lever of old and resinous grease.